I'm not convinced that the Second Wizarding War ended in 1998. Fred Weasley clearly dies in the battle at Hogwarts and these pages state that this was in 1998. The Weasley family tree on J.K. Rowling's website says differently though. She states that Fred died in 1997, which would make the year of the final battle '97 rather than '98.
I'm not sure whether the people creating the pages on here have made an error or if J.K. merely wrote down the wrong year and that, in fact, you were right in the first place?

Rowling made a mistake. According to the official timeline, the Battle of Hogwarts happened on May 2, 1998. It wouldn't be the first time Rowling made a mistake concerning the timeline: e.g. her books state that both September 2, 1995 and September 2, 1996 were Mondays. For more information, check Dating conventions. -- Seth Cooper(Owl Post) 00:34, 30 May 2009 (UTC)

Rowling has admietted that maths is not her strong subject. ShirleyA(The Quibbler) 01:20, 30 May 2009 (UTC)